From 01/04/2005 an '=' (equals) as the last significant character in this six character field will indicate an episode that should be excluded from the National Tariff Payment System tariff.

The position of the last character depends on any preceding characters eg 1st character if field is otherwise blank, 4th character if following 'OAT', up to a maximum of 6th position. This provides a general exclusion facility for unusual circumstances or where more specific rules regarding coding in other fields cannot be implemented due to local software restrictions.